There are commercial ladder racks which are mounted on vehicles, especially pick-up trucks, that permit ladders to be readily transported. Since many of these prior art ladder racks are formed of metal including steel, they are heavy and tend to rust or corrode. Further, some ladders are formed of fiber glass and these fiber glass ladders are sometimes damaged by sliding contact with the metal ladder racks. In some of the vehicle-mounted commercial ladder racks, loading and unloading of the ladder is available in one direction only (i.e. the rear). Finally, the hold down means of these prior art ladder racks are not effective in holding the ladders against movement in all directions.